Three-dimensional duplicating machine



Jan. 19, 1965 c. P. SCHNEIDER THREE-DIMENSIONAL DUPLICATING MACHINE 6 Sheets-Sheet 1 Filed June 12, 1961 FIG! Jan. 19, 1965 c. P. SCHNEIDER 3,165,975

HREE-DIMENSIONAL DUPLICATING MACHINE Filed June 12, 1961 6 Sheets-Sheet 2 Jan. 19, 1965 c. P. SCHNEIDER 3,165,975

THREE-DIMENSIONAL DUPLICATING MACHINE Filed June 12, 1961 6 Sheets-Sheet 3 M ,xw MW Jan. 19, 1965 c. P. SCHNEIDER 3,165,975

THREE-DIMENSIONAL DUPLICATING MACHINE Filed June 12, 1961 6 Sheets-Sheet 4 FIG-4 M/W/A "'HIII um F Hllllllllllli Wig a 5 K K144041751:

Jan. 19, 1965 c. P. SCHNElDER 3,165,975

THREE-DIMENSIONAL DUPLICATING MACHINE Filed June 12, 1961 6 Sheets-Sheet 6 F IG,8

as I 1 i 4 Mme/mm:

Wu 2 11/ rs,

United States Patent 3,1553% THREE-DHMENSIGNALBUPLTQATWG MACHHNE @urt P. Schneider, 4133 Dryden, St. Lonis,Mo. Filed dune 12, 961,521. No. 116,535 3 Claims. (til. 9il--l3.l)

The present invention relates to a machine for reproducing three-dimensional shapes, and particularly relates to a three-dimensional pantograph duplicating machine having a 1 to 1 reproducing ratio.

Three-dimensional duplicating machines are conventionally used to reproduce a pattern or copy master in a mold for castings, stamping dies and the like. There are numerous machines available for this purpose, but

the present machines tend to be very complicated, errpensive, difiicult to operate, do not normally produce a one to one ratio on the working block, require expensive hand made machined parts in their assembly, and often have vibration and involuntary motion in the arm hold ing the tracing and cutting elements.

All three-dimensional duplicating devices utilize a retary spindle to which a cutter is allixed, and a tracer spindle to which a tracer, sometimes called a stylus, is

' afiixed. The stylus is identical in shape and size to the cutter, and in most machines is guided by hand over a copy master in both horizontal and vertical directions. The cutter follows the movements of the tracer and reproduces the copy master in a work block.

In many constructions, the pivot bearings and vertical guide-ways are spaced at a considerable distance from the tracer and cutter spindles. The greater the spacing; the more vibration in the mechanism, particularly when the cutter is roughing a workpiece, and the less efficient' is the machine. Vibration is especially prevalent in en- 'larging machines where the cutter and tracer are on, the same side of the pivot point and the cutter is the most removed.

Most duplicatingmachinesutilize from six to eight dovetail slides to make the necessary adjustments, particularly in the work table, to properlyalign the workpiece relative to the copy master. These dovetail slides are expensive since they must be preciselymachined for proper functioning. 1

Most duplicating machines employ round nylon cord belts with facilities for belt adjustment in conjunction with step pulleys for increasing and decreasing speed. Under heavy loading with small drive pulleys, these belts have a tendency. to. slip, thereby causing speed and power loss in the cutting spindle.

One of the principal objects of the present invention is to provide a duplicating machine which produces a one to one reproduction ratio and which does not have any substantial vibration between the cutter and tracer spindles.

It is another object of the present invention to provide a machine which obviates to a considerable extent the need for precisely machined parts in its movement assemblies. lt is stillanother object of the present invention to provide amachine in which the work piece is precisely located on the work table by simple gauge blocks, without the use of precision machined work'adjusting slides and slide mechanisms.

Another object is to provide a three-dimensional duplicator which eliminates all dovetail slides.

Still another object of the present inventionis toprovidea novel mechanism for transferring rotativefmotion Patented Jan. 19, l9fi5 with respect to the side edges thereof by means of gauge blocks and the work piece then can be precisely and similarly located on the work table by using the same gauge Still another object is to provide a machine inwhich vide a machine in which the tracer and cutter spindles are closely positioned to the pivot bearing and the vertiv cal guides and horizontal bearings are close to the tracer and work tables to reduce the normal machine vibrations and increase the ruggedness of the machine.

Still another object isto provide a machine in which the contour tracing is controlled. by the operators right hand and a slidable pivot lever is provided to. allow the operators left hand .to follow the vertical irregularities Still another objectis to provide a machine in which i the vertical movement includes vertical guide pins housed spindles are closely positionedto the'pivot center of the machine to reduce vibration and in which both the tracing and cutting tables are equally visible and accessible to the operator. The present invention further comprises a. novel mechanism for tnansmitting rotary motion in a vertical direction.

In the drawings, wherein like numbers refer to like parts wherever they occur, i t

FIG. .1 is a top plan view of the present invention,

FIG. 2 is a partial sectionalview taken along'line 2 2 of FIG. 1, showing the base and vertical movement in section and. showing the horizontal graph mechanism in perspective. t

\ FIG. 3 is a partial sectional view taken along line 3- of FIG. -1 with a portion of the base and counterbalance rak s a y, i N t i FIG. 4 is a foreshortened partial sectional view taken along line 44 of FIG. 1 showing the drive mechanism in detail, t t l i F1G.5 is an enlarged partial sectional view taken along line 5- 5 of FIG. 1; i L

FIG. 6 is an enlarged sectional view taken along line ofFlGls,

, FIG. 7 is a partially broken top plan view of the lever actuating means for the vertical movement,

FIG. 8 is a sectional 'view taken along line 8"8 of FIG. 7, and i FIG. is a partially ting housing showing an electric "spindle positionedtherein;

in avertical direction by means of a vertically sliding ,ducin g machinein which the tracer table and the work FIG. 1 shows a top plan view of. the present three-di mensional reproducing machine M which includes a base 11 mounted. on legs 12, 21 tracing tablelfi', a work table l4, a vertical movement 15, a horizontal movement ,lf; a pantograph control mechanism 17 and a drive mechanism l8 poweredby a driviemeans19. t

The tracing table 13 andthe worktahle 14 are pro vided with longitudinal T shaped slots Ell which retain clamps to fasten a model and a work piece (not shown) respectively to tables. The tracing table 13 and the three-dimensional movement and pantobroken sectional view of the cut V beam 26 below the'base 11.

V and are vertically slidable in linear ball bearing assemblies 21a (commonly known as ball bushings) mounted in openings 22 in the base 11 and therefore fix the tables 13 and 14 against horizontal movement but allow vertical movement thereof. 7 The linear ball bearing assemblies 1 21a inculde a bushing retainer 21b fastened to the base 11, a sleeve 21c and oblong circuits of ball bearings 21d which roll freely in tracks 21:: positioned in the sleeve 210.' The use of the linear ball bearing assemblies 21a eliminates the heretofore necessary hand machined dovetatil slide adjustment mechanisms, with resultant savings in cost.

Vertical adjusting mechanisms 23 and 24, can be hand actuated to adjust the tables 13 and 14 upwardly or downwardly to compensate for differently sized copy masters. Each of the mechanisms 23 and 24 is identical and only th ework table adjusting mechanism 23 will be described in detail. The mechanism 23 includes a stationary screw 23a fastened to the underside of the work table 14, a miter gear 23b rotatively housed in a bracket and the friction in these systems.

the bushing retainers 29 provide relatively frictionless vertical movement for the pins 2 7 and 28 in the bushing retainers 29. The linear ball bushings 343, the pins 27 and 28 and the bushing retainers 2% all are readily available items of commerce and provide vertical adjustment of the present mechanism without any expensive machining of the relatively movable parts.

A counterbalance mechanism 31 is fixed to the vertical movement 15' and consists of chains 32 anchored to the bottom cross beam 26 and running over sprockets 33 to a counterbalance weight 34 which overcomes the weight of the vertical, horizontal and pantograph mechanisms A dust cap 35 protects the moving parts of the vertical movement 15.

The horizontal movement 16 includes an impeller beam 36 pivotally fixed in a main horizontal bearing bracket 37 which is fixed to the top cross beam 25. The impeller beam 36 is pivoted at its center to the main bearing bracket 37 and the pivot point 38 is vertically aligned with the center of the front pin'27 (FIGS. 2 and 3). A tracer oscillator 39 is pivoted at 4th to the end of the impeller beam 36 positioned over the tracing table 13, and

a cutter oscillator 41 is pivoted at 42 to the end of the 23c fixedto the base plate 11, and a coacting one to one miter gear 23d fixed to a shaft 23 rotatively journaled in shaft bearing brackets 23 fixed to the base 11. A graduated hand wheel23g is fixed to the shaft 23c and a pointer 23h depends from the base 11. The hand wheel 23g is graduated in thousandths of an inch for accurate adjustment'of the table 14.

The tables 13 and 14 have inboard side edges 13a and 14a and Work locating edges 13b and 14b respectively. The table side edges 13a and 14a are parallel to and equally spaced from the line connecting the centers of the front pin 27 and the rear pin 28. The table Work locating edges 13b and 14b are perpendicular to the line connecting the centers of the front pin 27 and the rear pin 28 and are equally spaced to the front and rear of the front pin 27. V I r The tables 13 and 14 are rectangular and preferably of equal size. on the base 11 the same as the tracing table 13 would be, if the table '13 were rotated 180 aboutthe center of the front pin 27. Therefore, when a copy master. is positioned on the tracer-table 13, it can be located on the table 13 with respect to its distance from the inboard edge 13a and the work locating edge 1312 by means of standard gauge blocks. f p

To produce an exactcopy, a work object must be similarly located on thework table 14. The work object is located on the work table 14 by using the same guide blocks as were usedtolocate the copy master on the tracer table 13. Thdistance from the tracer table inboard edge 13a to the copy master is laid off from the work table edge 14a to the work object, and the distance from the tracer table locating edge 13b to the copy master is laid "off from the work table locating edge 14b to the work object. v

Thus, the work object is positioned on the work table 14, exactly 180 fronrthe copy master located on the tracer table 13 The work object is also equally spaced with the copy master from the center of the front pin27, so that the copy master is exactly reproduced in the work object; l

; The vertical movement 15 includes a top vertical cross beanr25 above the base 11 and a bottom vertical cross The beams 25 and 25 are spaced in vertical alignment'lb'y a front pin 27 and a rear pin 28. .The pins 27 and 28 are PPsitioned Within and are vertically movable in bushing retainers 2? fixed to In effect, the work table 14 is positioned impeller beam 36 positioned over the cutting tableld.

The tracer oscillator 39 includes a tracer quill housing 43 having an opening 44 adapted to receive a tracer quill 45. A tracer spindle and chuck 45a having a threaded upper end 45b is seated in the tracer quill 45 and is the base 11 Linear ball bearing assemblies 30 (similar adapted to hold a stylus 45c at the lower end thereof. The tracer spindle 45a is vertically adjusted with respect to the housing 43 by a micrometer nut 45d mounted in a bracket 45e on the housing 43. 7 a

A bracket 46 houses a pivotal connection 47 connecting the tracer oscillator 39 to the pantograph mechanism 17. The pivot 47 is vertically spaced from and aligned with the center of the tracer quillreceiving opening 44.

The cutter oscillator 4-1 includes a cutter housing 48 having an opening 49 therein adapted to receive a cutter spindle 50. A bracket 51 houses a pivotal connection 52 connecting the cutter oscillator 41 to the pantograph control mechanism '17. The pivot 52' is vertically spaced from and aligned with the center of the cutter spindle receiving opening 45'.

The cutter spindle 54) is adapted to receive a cutter at one end and is connected to the drive mechanism 18 at the other upper end.

The pantograph control mechanism 17 is pivotally fixedto a fulcrum stud 53 at pivot 54. The fulcrum stud 53 i;7fixed to the top of the main horizontal bearing bracket As hereinbefore mentioned, the pantograph control mechanism 17 also is pivotally fixed at pivot points 47 and 52 to the horizontal movement 16. Therefore, the horizontal movement 16 and the pantograph control mechanism 17 move in a vertical direction with the vertical movement 15. As the pantograph control mechanism 17 controls and synchronizes the horizontal movement of the tracer spindle 45 and the cutter spindle 5t (as will be more fully explained hereinafter), the present 56 respectively. The linkage of the pantograph mocha nism 17 in'conjunction with the. propeller beam 36 andf the oscillator pivotal connections and 42, controls the horizontal motion of the tracer quill 45 and thefcutte-r' spindle 50.

between points 59 and 54- is e-qualto the distance between the points 54 and 62; the distance between points 42 and.

" opening and the counteibore 77.

54 is equal to the distance between the points and 4:3; and the distance between points 52 and 42 is equal to the distance between the points 43 and 47. When these distances are established, movement of the tracer spindle 45 is followed by equal and corresponding movement of the cutter spindle 5% in a horizontal direction.

The drive mechanism 13 includes a vertically mounted motor drive means 19, which preferably is a variable speed DC. electric motor (FIG. 4). The motor 19 is fixed to a motor bracket 63 which is fastened onto the base 11. The motor bracket 63 also includes an extension 64 extending inwardly toward the work table 14. The motor 19 includes a shaft 65 and a drive pulley 66 fixed thereto. The pulley 66 has grooves in the base which are adapted to receive lugs or teeth on a steel cable reinforced rubber drive belt 67. The belts 67 are known as \Voods Timing belt device and do not slip under heavy cutting loads. The belts 67 are available from T. B. Woods Sons Company of Chambersburg, Pennsylvania. Ordinarily round nylon cord belts and stepped variable diameter pulleys are used with a constant speed motor. The present invention uses notched constant diameter pulleys and. a variable speed motor in combination with the lugged belts to eliminate the slippagewhich otten occurred when a heavy load was combined with a small diameter drive pulley.

'Therotation of the motorshaft 65 must be transferred ,to cutter spindle 56X. To do this, the motion must not only be transferred laterally, but also vertically, since the rnotondrivepulley 66 is vertically spaced from a driven pulley v68 keyed to the cutter spindle 50. Also, the drive pulley. 66 is fined both vertically and horizontally, where- .as the.,dutter spindle pulley oaisrnovable both vertically Yenicalniotion transmittr'means 69, (showrijin ros. 14- 6) isfadapted to therotative nflotion'frornlthe motor pulleylfi'dinha vertical direcflon' to the cutting "rig spindle. isfmoved in vertical and 'Thoriionial directions. fWhen-luggeddrive Ibeltsareiuoed, thelbelts must be maintained parallel to l s I 5 he .pu v 0; ieve et s w p i n Whereas withlvariable diameter; pulleys and ,roundbelts, belts kantedfto cpmpensate. for; the vertical movementbfiflieicuttingspindle. I I

. The verticalimcfion ltrarismitter. 69 includes a vertically positioned} I r 'sii inillejfl'having each of'its ends 71 and .72, neckeaaown'ans rot'atively housed in a pair of bracket arms 73 shelf/'4 fixe dito" the rnotor hraclret extension uny 7 5 is jfixed to, thelower end 71 of the outer 1s'pindle'70' adjacent ,tofits connection to the bracket arm 13. Th nieyjzs recei me b,el t 67 which ,is the motor drivepull'ey 66,1 and rotates the outer spindle "a tja dependent upon the speed of the motor 19. iTheouter spipdld'lil'is provided with an opening 76 in Ti lower'end 71; a counterhore 7.7 in its upper end 7.2 a' nd ari enlarged cavity 7Stherebetween. The cavity 7,

is an opensided slot formed completely through the outer lspii ndl e 7 0 intermediate of and in communication with the spindle pull y 3 7 3 99 An inner spindle 79 the outer spindle and is vertidally movable therein through the opening 76, theslot 78 and the counterbore 77. Linear ball bearing assemblies 80 permit relatively frictionless vertical movemerit of the inner spindle 79 iii the'outer spindle 70. An opening 82 aligned'with the outer spindle slot 78 is prois housed vided through the inner spindle 79. A torque pin 83 having end mounted ball bearings assemblies affixed to either end thereof is positionedin the inner spindle opening 82 and the bearing assemblies 84 ride in the outer spindle slots 73.

Thus, the inner spindle '79 is rotatably locked to the oute'r spindle 79, but the inner spindle 79 is axially and vertically movable relative to the outer spindle Therefore, the rotative motion from the motor pulley 66 is transmitted to the inner spindle 79 through the driven by r 6 pulley 75 and the outer spindle 70. Since the inner spindle 79 is axially slidable in the outer spindle 78, the rotative motion impacted to the inner spindle can be further transmitted from different vertical positions of the inner spindle 79.

The inner spindle 79 has an end extension 85 extending upward from the outer spindle upper end 72. The inner spindle end 85 is rotatively fixed to a lifting bar racket 86 fastened to one end of a lifting bar 87. An Se 1 z'ensovably fastened by screws 89 to the other end of the bar 87. The arm 88 is pivotflly connected to the member 56 and to the cutter spindle bracket 51 at the pivot 52.

Therefore, the inner spindle 79 is positivel connected to the pantograph mechanism 17 and is vertica ly movable with the horizontal movement 16. v

A driven grooved pulley 9G is keyed to the inner spindle end extension 85 to rotate therewith and is positioned adjacent to the lifting bar bracket 86. A logged rubber belt drive 91 connects the pulley 91} with the pulley 63 fixed to the cutter spindle 50. Thus, the rotation of the motor shaft 65 is transmitted to the cutter spindles) through the drive pulley 66, the belt drive 67, the pulley 75, the outer spindle 78, the inner spindle 79, "the pulley 90, the belt drive 91 and the pulley 68;. a As the pulley is fixed to the] inner spindle 79 and the pulley 68 is fixed to the cutter spindle 50 and the inner spindle 79 moves vertically with the cutter spindle 56 because of the lifting'bar 87, the belt 79 is maintained in its original parallel alignment withtthefbase'fl; When the cut ter spindle moved in vertical direction, the inner spindle 79 mov'es axially th o t er spindl 0, but continues to rotate tli'erew'ith'b" au ofthe F it et q p fi ia 1 l$ l $8 v The' speed of theflcuttifig spindle 'SDord from 800-10300 rpm. H I

is inserted inllhfilopenmg 1 s e of m afis p sb m 34, 1

A S aw 1116 9 1 '59 dh l motor, thedrive and verfrcalfjmoye the amas is licensees-s y, sit-(re rise y y bar 87 is dis'conn'ected 'from 'the pantograpl'i mechanism 17 by removing the screws 89 and disconn ting rm 88 tr om the,bar S7, f f .Wheh thebpeiatorfstands in frontfofthe base 11 he i sf presen'tediwitl'i la cleafviewof botli'the: mo'delanrl the work piece, since these are 'fixed to" the, tracer t'able 13 to the cutter table 14 and thef' tab les themselves are at about a 45 angle to' the frontof the machine 10. Present machines ordinarily aligiijZ-the model with the from/the operator. t

Also, thertrac'er spindle 4 5 and the cutter spindle 50 are positioned in close proximity to the center of the ,work plecefand thus true of the re entment removed machine 10 equidistant onbither side of the vertical tnovementj ls which eliminates a considerable portion of the vibrat on and jumping which often ,occurs'whn either the cutter or the tracer is far removed from the main horizontal pivot point, 'as is often the situation when a bar or beam is used which is pivoted at one end with the cutter and tracer positioned out on the beam. i

A further improvement in the present invention is shown in FIGS. 7 and 8 and includes a lefthand actuator assembly 92'for the vertical movement 15. The assembly 92 includes a hand lever 93 pivoted at one end 94 to a bracket 95 mounted on the underside of the base 11. A finger 96 is fastened to the underside of the bottom cross beam 26 of the vertical movement 15 and is aligned with the handle 93. A bracket 97 is pivoted at 98 to the lever 93 between its ends and is slidable on the finger 96.

invention;

Thus, the lever 93 is pivotally connected to the base 11 and there is a slidable pivot connection between the vertical movement 15 and the lever 93. The slidable bracket 97 is necessary because the pivot point 98 moves closer to the bottom cross beam 26 as the vertical movement 15, including the cross beam 26, moves upwardly.

By means of the actuator assembly 92, the operator can operate the horizontal movement 16 with his right hand and the vertical movement 15 with his left hand. This often is of considerable importance, since an operator standing at such a machine for eight hours or more will have considerable fatigue in one hand while the other hand is doing almost nothing. The present invention obviates this difiiculty in a compact and etlective manner.

Another advantage of the present machine is that the machine center, defined by the centersof the front pin 27, the pivot 38, the fulcrum stud 53 andthe pivot 54, is the center of the horizontal movement 16, the fulcrum of the pantograph assembly 17 and is on the center line of the vertical movement 15.

I A bracket 99 houses a micrometer stop 100 which engages a tongue 101 on the top crossbeam to limit vertical movement to a predetermined point. I

Thus, the operator is given three difierent independent adjustments of the vertical height of the stylus with respect to the cutter; The tracer table ,13 can be adjusted, the position of the tracer spindle a can be adjusted by the micrometer nut 45d, and the'micrometer .stop' ltltl can be adjusted to limit verticatmovementp These adjustments are, necessary"whena cavity isbeing'tracedin toughened steel toallow the cutter to form the cavityin small incrementsgwhile still tracing' the outline of the cavity f'with th'efstylus.' f i Horizontal movement is jarovided by the operator grasping the tracer oscillator"39 and movingthetracer quill 45over the copy master. 1 f

'I'heimpellerbeam1'36'preferably has about 90 -10Of rotativ'e movement, while each of the oscillatgrs tig and 41 has'about 120 rotative movement. 1 M Q f f Thus it is seen that thefpresent' yentionfprovides a three-dimensional reproducing' rnachihewhich aehieve s all the objects andadvantagessought'therefor;

This invention is intended 'tolboverall' modifications oi the 'efarhples of the invention herein chosen for, purposes of the disclosure, which dofjnotcom stitute departures from the spiritfand scopeotthe l. A three-dimensional reproducing machine'comp'ris ing a base, a tracer tabIe ajW rk table, means adapted for vertical movement verticallymovable'in linearball bushings housedin said base, means adapted for hgriz qntal movement pivotally carried by vertical' move ment means and movable therewith, said 'horizontal'moverhent means including a 'bear'n pivotally suppo'rtirig aftrac er 'spindlea'n'd a cutter spindle, means rgenmni t i movement of said tracer and cutter spindles intwofhorizontal directions, drive means at a different vertical elevation from said cutter spindle, and a drive transmission for communicating the rotary motion from 'saiddrive meansto said cutter spindle, saiddrive transmission'includin'g grooved constant diameter pulleyson 'said cutter spindle and said drive means, a vertical motion transmitting assembly including a pair of spindles rotatable in common and longitudinally relatively movable, grooved constant diameter pulleys on each of said spindles, a first belt having lugs engageable with the pulley grooves conecting the drive means pulley with the pulley on one of said spindles, a second belt having lugs engageable wtih the pulley grooves connecting the cutter spindle pulley with the pulley on the other of said spindles, and means for vertically shifting the spindles with respect to each other, said means being tied to the vertical motion of said cutter spindle, whereby the belts are maintained in constant horizontal alignment.

said cutter spindle.

2. A three-dimensional reproducing machine comprising a base, a tracer table, a work table, said tables being angularly aligned with respect to the front of the machine, means adapted for vertical movement centered between said tables, said vertical movement means including linear ball bearing assemblies positioned in said table, top and bottom cross beams positioned above and below the tables, pins connecting the cross beams, said pins being vertically movable in said linear ball bearing assemblies, and a hand actuated lever pivoted to the base and pivotally and slidably connected to the vertical movement means to raise and lower said vertical movement means, means adapted for horizontal movement including a propeller beam pivoted at its center to the vertical movement means and supported by said vertical movement means, oscillators pivotally housed in the ends of said propeller beam, a tracer spindle positioned in one of said oscillators and vertically aligned with the tracer table, a cutter spindle positioned in the other of said oscillators and vertically aligned with the work table, pantograph means for synchronizing horizontal movement of said tracer and cutter spindles including a series of arms pivotally interconnected to form a parallelogram linkage movable in two dimensions about a main pivot point vertically aligned with the vertical movement, one of said arms having an extension pivotally connected to the tracer oscillator in vertical alignment with the tracer spindle, the parallel arm being pivotally connected intermediate its ends to the cutter'oscillator in vertical alignment with the cutter spindle, a cross arm of said parallelogram linkage being'pivotally connected to said horizontal movement means at the main pivot pointv said arms being dimensioned so as to maintain the tracer-spindle, the main pivot, and the cutter spindle in a straight line, variable speed drive means, a drive pulley on said drive means, a driven pulley 'on'said cutter spindle, said pulleys being maintained at difierent variable elevations during operation of the machine, means for transmitting rotative motion from said drive means to said cutter spindle includinga bracket, afirst spindle rotatably housed in said bracket, a pulley fixed tosaid first spindle and horizontally aligned 'with the drive pulley, a belt connecting said pulleys, said first spindle being provided with an openended bore a second spindle axially movable in said bore, means Iim'iu'ng'said first and second spindles to common rotativejmotion while permitting relative axialmotion, a pulley fixed to said second spindle and horizontally :ahgned with the driven pulley on said cutter spindle, a belt connecting said pulleys, andmeans for effecting vert cal movement of said second spindle, said means being pivotally linked to the pantograph mechanism at a point vertically aligned with thefcutter spindle, whereby said pulley belts are maintained in horizontal alignment durng vert cal movement of said cutter spindle and tension in said belts is maintained during horizontal movement of 3. A three-dimensional reproducing machine comprismg a base, a tracer table, a .work table, means adapted for vertical movement vertically movable with respect to said base, means adapted for horizontal movement pivotally carried by said vertical movement and movable therewith, said horizontal movement means including a beam pivotally supporting a tracer spindle and a cutter spindle, pantograph means synchronizing the movement of said tracer and cutter spindles in two horizontal directrons, drive means at a different vertical elevation from sa1d cutter spindle, and a drive transmission for commurucating the rotary motion from said drive means to said cutter spindle, said drive transmission including a bracket. a first spindle rotatably housed in said bracket a palley fixed to said first spindle and horizontally aligned with the drive pulley, a belt connecting said pulleys, said first spindle being provided with an open-ended bore, a second spindle axially movable in said bore, means limiting said first and second spindles to common rotative motion which permits relative axial motion, a pulley fixed to said second spindle and horizontally aligned with the driven pulley on said cutter spindle, a belt connecting said pulleys, and means for effecting vertical movement of said second spindle, said means being pivotally linked to the pantograph mechanism at a point vertically'aligned with the cutter spindle, whereby said pulley belts are maintained in horizontal alignment during vertical movement of said cutter spindle and tension in said belts is maintained during horizontal movement of said cutter 10 spindle. 1

References @ited in the file of this patent UNITED STATES PATENTS Singer Apr. 10, 1849 Gilbert July 18, 1933 ZWicl-c Oct. 17, 1939 Etzler May 8, 1951 Compton Sept. 16, 1952 Stuart et a1 July 14-, 1953 Grove et al. 1---- Nov. 29, 1960 Gunderson Sept. 19, 1961 

1. A THREE-DIMENSIONAL REPROUDCING MACHINE COMPRISING A BASE, A TRACER TABLE, A WORK TABLE, MEANS ADAPTED FOR VERTICAL MOVEMENT VERTICALLY MOVABLE IN LINEAR BALL BUSHINGS HOUSED IN SAID BASE, MEANS ADAPTED FOR HORIZONTAL MOVEMENT PIVOTALLY CARRIED BY SAID VERTICAL MOVEMENT MEANS AND MOVABLE THEREWITH, SAID HORIZONTAL MOVEMENT MEANS INCLUDING A BEAM PIVOTALLY SUPPORTING A TRACER SPINDLE AND A CUTTER SPINDLE, MEANS SYNCHRONIZING THE MOVEMENT OF SAID TRACER AND CUTTER SPINDLES IN TWO HORIZONTAL DIRECTIONS, DRIVE MEANS AT A DIFFERENT VERTICAL ELEVATION FROM SAID CUTTER SPINDLE, AND A DRIVE TRANSMISSION FOR COMMUNICATING THE ROTARY MOTION FROM SAID DRIVE MEANS TO SAID CUTTER SPINDLE, SAID DRIVE TRANSMISSION INCLUDING GROOVED CONSTANT DIAMETER PULLEYS ON SAID CUT- 